JPH0537945A - Index tube - Google Patents

Abstract

PURPOSE:To stabilize the output level of an index signal. CONSTITUTION:Groups of primary color elements R, G, B consisting of strip-like self-emitting type picture elements are arrayed on the display face of the tube body of an index tube 8 at a prescribed pitch and index elements I for generating index signals are arranged between the groups of the elements R, G, B in the scanning direction. The fluorescent face 10 of the tube 8 is concentrically divided from its center into four ranges a to d e.g. and the index elements I included in respective ranges a to d are set up so that their width is successively widened at the rate of 0.1, 0.2 and 0.3 in respective ranges b to d based upon the center range a to be a reference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an index tube used when a plurality of display elements are arranged to form a large screen display device.

[0002]

2. Description of the Related Art As a device for displaying a so-called television signal on a large screen, conventionally, a plurality of display devices such as color cathode ray tubes are assembled vertically and horizontally to display images in a divided manner.
There is also known a device in which a large number of single-color or three-primary-color display elements are arranged in a matrix to display each pixel. However, in the case of using these devices, in the former case, the non-display portion such as the joint of the cathode ray tube becomes a black line and is formed on the display surface, which hinders the viewing of the image. In the latter case, there is a limitation in downsizing the display element, and the picture elements become rough, so that viewing from a close range cannot be performed well.

On the other hand, the applicant of the present application has previously proposed a large-screen display element and device for solving the above-mentioned drawbacks (see Japanese Patent Application Laid-Open Nos. 2-178692 and 2-262190).

That is, A in FIG. 3 is a side sectional view of the large screen display element (index tube) described above, and B in the same figure is a front view thereof. In this figure, reference numeral 1 denotes a tube body, and this tube body 1 is formed of a front panel 2 made of glass and a funnel portion 3 integrated with a neck portion.

The front panel 2 has a strip-shaped fluorescent display portion (self-luminous type picture element) on its inner surface, which serves as a plurality of sets of picture elements. Body trio 4 is formed. As shown in the figure, this phosphor trio 4 is composed of blue, red, and green phosphor layers B, R, and G having a length L and a width W, and is formed on the display surface 5 in a predetermined manner. The pitch is P and the longitudinal direction is arranged along the horizontal direction. A light absorption layer is formed on the surface other than the phosphor layers B, R, and G. Further, an index element I indicated by a broken line is provided on the light absorption layer between the phosphor trio 4 and in the surface scanning direction. It should be noted that the index element I generates, for example, ultraviolet rays having a predetermined wavelength in response to irradiation with an electron beam e described later. The phosphor trio 4 and the index element I are formed by a printing method, a slurry method, or the like.

The front panel 2 and the funnel portion 3 are joined to each other using frit glass. In this example, a step portion is provided on the inner peripheral edge of the flat front panel 2, and the funnel portion 3 is joined so as to fit into the step portion. The outer peripheral surface of the portion of the funnel portion 3 joined to the front panel 2 is formed to be perpendicular to the surface of the front panel 2.

Reference numeral 6 represents an electron gun, and a device for emitting a single electron beam e is used as the electron gun 6. As will be described later, the single electron beam e is sequentially modulated by the video signals of the three primary colors by, for example, switching, and each of the blue phosphor layer B, the red phosphor layer R, and the green phosphor layer G of the phosphor trio 4 is modulated. As if hitting, the deflection yoke 7 scans vertically and horizontally. The shape of the single electron beam e is preferably a horizontally long beam shape, for example, an elliptical shape, so as to correspond to the shape of the phosphor layer. Further, in the scanning of the single electron beam e in this example, since the phosphor trio 4 is arranged in the longitudinal direction along the horizontal direction, the conventional scanning method, that is, the phosphor layers B, R, while scanning horizontally, Rather than hitting G, the phosphor layers B, R, G are scanned vertically.
You are supposed to hit. Further, scanning is performed so that the index element I is also hit, as described later.

The index tube 8 having such a structure
As shown in FIG. 4, a large-screen display device in which the pitch P of the phosphor trio 4 is constant between the index tubes 8 as shown in FIG. .. As a specific example, the above-mentioned index tubes 8 are 30 in the vertical direction and 40 in the horizontal direction, for a total of 12 tubes.
A large-screen display device is configured by arranging 00 pieces.

Further, FIG. 6 shows a circuit structure for sequentially modulating the above-mentioned single electron beam e with video signals of three primary colors by switching, for example. In this figure, a signal from an antenna 11 is supplied to a tuner 12 to receive a desired television signal, and this received signal is supplied to a detection circuit 13 to demodulate a composite video signal. This demodulated signal is supplied to one fixed contact of the input selection switch 14. Further, the composite video signal supplied to the video input terminal 15 is supplied to the other fixed contact of the input selection switch 14, and the signal selected by this switch 14 is supplied to the color demodulation circuit 16 to generate blue B, red R and green. The three primary color signals of G are extracted.

On the other hand, the signal selected by the switch 14 is supplied to the sync separation circuit 17 to separate the horizontal and vertical sync signals, and these sync signals are supplied to the timing control circuit 18.
Is supplied to. The timing control circuit 18 first forms a sampling signal Sp obtained by dividing the horizontal effective screen period into, for example, 320 equal parts, and the sampling signal Sp is commonly supplied to the A / D converters 19B, 19R and 19G of three systems. .. The A / D converters 19B, 19R and 19G are respectively supplied with the three primary color signals of blue B, red R and green G from the color demodulation circuit 16 described above. Then, for example, 8-bit digital signals A / D converted at the timing of the sampling signal Sp are respectively stored in the field memory 20B,
It is supplied to 20R and 20G.

Further, the sampling signal Sp and the start signal Ss corresponding to the upper end of the effective screen from the timing control circuit 18 are supplied to the address generating circuit 21, and the address generated by the address generating circuit 21 is stored in the field memory 20B. , 20R, 20G. As a result, for example, 320 × 240 (the number of horizontal scanning lines) that constitutes the field in one field period of the video signal
= 76800 video signal data are written in the field memories 20B, 20R and 20G for each primary color. Further, the field memories 20B, 20R, and 20G have a so-called double buffer structure, each of which has a storage capacity of 2 fields, and while one field is being written, another field is stored. It is designed to be read.

The field memories 20B, 20R, 2
The video signal data read from the 0G is the 64 picture element memories 22B and 22 provided for each of the above-mentioned index tubes 8.
It is supplied to R and 22G. Here, the index tubes 8 are constituted so as to constitute a unit by a total of 12 arrays, for example, three in the vertical direction and four in the horizontal direction. Therefore, the large-screen display device described above is configured by arranging these units in the vertical direction and the horizontal direction, respectively, 10 units each, for a total of 100 units. Therefore, the 64 picture element memories 22B, 22R, and 22G are provided on a single substrate 23 together with twelve memories 22B, 22R, and 22G for each unit, and 100 substrates 23 are prepared.

The sampling signal Sp and the start signal Ss corresponding to the upper end of the effective screen from the timing control circuit 18 are supplied to the address generating circuit 24, and the address generated by the address generating circuit 24 is 64 picture elements. It is supplied to the memories 22B, 22R and 22G. As a result, 64 pieces of video signal data displayed on the corresponding index tube 8 during one field period of the video signal,
64 picture element memories 22B, 22R and 22G are written for each primary color. Further 64 picture element memories 22B, 22R, 22
G has a so-called double buffer structure, and each has a storage capacity of 2 × 64 picture elements, and one of them has 6
While writing to the four picture elements, the other 64 picture elements are read out. Further, this reading corresponds to the detection of an index signal which will be described later and the 64 picture element memory 22.
B, 22R, and 22G are sequentially performed.

These 64 picture element memories 22B, 22R, 22
The video signal data read from G is collected into one system, and the D / A converter 2 is provided for each index tube 8.
5 is supplied. Further, the video signal from the D / A converter 25 is supplied to the video amplifier 27 through the gate circuit 26, and the video signal from the video amplifier 27 is supplied to the index tube 8. Also, the timing control circuit 18
Is supplied to a horizontal / vertical deflection circuit 28 to form a horizontal / vertical deflection signal which will be described later. This deflection circuit 2
The deflection signal from 8 is supplied to the deflection yoke 7. As a result, a video signal of 64 picture elements is displayed for each index tube 8, and the total of 1200 index tubes 8 is 320 (the number of horizontal picture elements) × 240 (the number of horizontal scanning lines).
Is displayed. Reference numeral 100 is a power supply block, which forms the high voltage and various grid voltages supplied to the index tube 8. The power block 100 is provided for each unit.

Further, the signal from the timing control circuit 18 is supplied to the index carrier generation circuit 29, and the index carrier signal from this generation circuit 29 is supplied to the gate circuit 26 during the scanning period in which the electron beam e, which will be described later, strikes the index element I. Is supplied to. Each index tube 8 is provided with means 9 for detecting the index signals from the index element I, and the index signals from these detection means 9 are supplied to the index memory 31 through the index amplifier 30. In addition, the signal from the timing control circuit 18 is the index memory 3
1, and the index signal is stored at the above scanning timing. Further, the stored index signal is read during the next scanning period, and the 64 picture element memory 22 is read according to the read index signal.
Sequential read switching of B, 22R, and 22G is performed.

FIG. 7 shows the horizontal and vertical deflection signals described above. That is, in the above-described device, the fluorescent material layers B, R, and G are tapped while being vertically scanned, and horizontal surface scanning is performed. Therefore, a synchronization signal for one field period shown in A of the figure and a timing signal obtained by dividing this signal into 16 equal parts are supplied to the horizontal and vertical deflection circuits 28 as shown in B of the figure. Then, these signals form a sawtooth-like vertical deflection signal as shown in C of FIG.
A stepwise horizontal deflection signal is formed as shown in FIG.
As a result, scanning is performed in which the electron beam e as shown in FIG. 8 hits the phosphor layers B, R, G and the index element I. ~ Indicates the order of scanning.

However, in this apparatus, the waveform of the index signal taken out through the index amplifier 30 is as shown in FIG. 9A during one scanning period in the vertical direction, for example. Further, it is as shown in B of the same figure during one scanning period in the horizontal direction. When the light collecting plate is provided as the index signal detecting means 9 on one surface of the funnel portion 3 of the index tube 8, the level decrease is caused by the angle at which the light collecting plate receives the ultraviolet ray from the index element I. It is physically generated by the influence of.

When the level of the index signal fluctuates in this way, 64 is generated in the part where the level is lowered.
The period during which the pixel memories 22B, 22R, and 22G are sequentially read becomes unstable, and the electron beams e to the phosphor layers B, R, and G are emitted.
Irradiation becomes uncertain. For this reason, the brightness of the display is reduced in these portions, and the uniformity of the display is impaired.

On the other hand, it is possible to consider a method of providing the above-mentioned light collecting plate on two or more surfaces to improve the level reduction.
However, providing light collectors on two or more surfaces is
This leads to an increase in manufacturing cost, such as an increase in work steps for assembling the index tube 8.

[0020]

The problem to be solved is that the output level of the index signal decreases from the central part to the upper, lower, left and right directions, thereby impairing the uniformity of display.

[0021]

According to the present invention, primary color elements R, G, B composed of strip-shaped self-luminous picture elements are formed on a display surface of a tubular body.
In the index tube in which the index elements I for generating the index signal are arranged between the groups of the primary color elements and in the surface scanning direction, the area of the index elements I is The index tube is characterized in that the peripheral portions b, c and d are set wider than the center a.

[0022]

According to this, by setting the area of the index element to be wider from the center toward the periphery of the phosphor screen, the output level of the detected index signal is stabilized,
A uniform display can be obtained.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a primary color element R consisting of strip-shaped self-luminous pixels is formed on a display surface of a tube body of an index tube 8.
A group of G and B is arranged at a predetermined pitch, and an index element I for generating an index signal is provided between the group of primary color elements R, G and B and in the surface scanning direction. The phosphor screen 10 of the index tube 8 is concentrically divided from the center into, for example, four ranges a, b, c, d, and the index element I provided in each of these ranges is based on the center range a. 1 for each range b, c, d
It is set so that it gradually becomes wider at a ratio of 20%, 30%, and 30%.

As a result, in this device, the index signal emitted from the index element I is increased according to the widened width, and the output level of the index signal detected by the increase of this signal is stabilized.

That is, in the above-mentioned device, the output level of the index signal in one vertical scanning period when the widths of the index elements I are equal is, for example, A in FIG.
As shown in, the central part is 1 and 0.9 upward and downward.
It changes like 3, 0.83, and 0.66. Further, even during one horizontal scanning period, as shown in B of FIG.
Is changing like. Therefore, as described above, the index element I is divided into ranges b, c, d with reference to the center range a.
By setting the width to gradually increase at a rate of 10%, 20%, and 30% for each, the above-mentioned fluctuation of the output level is offset and detected by the increase of the index signal due to the expansion of the width. The output level of the index signal is stabilized.

Thus, according to the above-mentioned device, the area of the index element I is around the phosphor screen 10 (ranges b, c, d).
By being set wider than the center (range a),
The output level of the detected index signal is stabilized, and uniform display can be obtained.

In order to further enhance the effect, the current of the electron beam e for scanning the index element I may be increased for each of the ranges a, b, c, d described above.

[0028]

According to the present invention, by setting the area of the index element to be wider from the center toward the periphery of the phosphor screen, the output level of the detected index signal can be stabilized and uniform display can be obtained. I can do it.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an example of an index tube according to the present invention.

FIG. 2 is a diagram for explaining the explanation.

FIG. 3 is a side view and a front view of the index tube.

FIG. 4 is a diagram for explaining the explanation.

FIG. 5 is a diagram for explaining the explanation.

FIG. 6 is a circuit diagram of a large screen display device.

FIG. 7 is a waveform diagram of a deflection signal.

FIG. 8 is a diagram for explaining scanning.

FIG. 9 is a waveform diagram of an index signal.

[Explanation of symbols]

 8 Index tube 10 Phosphor screen R, G, B Primary color element I Index element a, b, c, d Range

Claims (1)

Claims: 1. A group of primary color elements consisting of strip-shaped self-luminous picture elements are arranged at a predetermined pitch on a display surface of a tubular body, and between the group of primary color elements and An index tube in which an index element for generating an index signal is arranged in the surface scanning direction, wherein the area of the index element is set wider toward the periphery of the phosphor screen than from the center.